LOS ANGELES, California, November 22, 2005 (ENS) -
Rising levels of intense underwater sound produced by oil and gas exploration, military sonar and other human sources are threatening the survival of whales, dolphins, fish and other marine species, concludes a report released Monday by the Natural Resources Defense Council (NRDC).

In the underwater darkness, marine mammals use their own sounds and sounds made by other marine animals to navigate while migrating, to locate each other over great distances for mating, to find food, avoid predators, and care for their young.

High decibel noise can interfere with all of these activities, testing the ability of marine animals to survive. Examinations of whales that have beached themselves after they were exposed to sonar used in military battle exercises show the whales were bleeding internally around their brains and ears.

"Ocean noise is an insidious form of pollution. The tremendous damage it is doing to life in the sea is becoming more evident with each passing year," said Michael Jasny, the report's principal author.

Carcasses of beaked whales are removed from the beach after a mass stranding in the Canary Islands, 2002. (Photo courtesy NRDC)

The report "Sounding the Depths II: The Rising Toll of Sonar, Shipping and Industrial Ocean Noise on Marine Life," is accompanied by a five-minute movie narrated by actor and environmentalist Pierce Brosnan and produced by the firm Imaginary Forces. The film, "Lethal Sound," is about harm to marine mammals from high-intensity military sonar and seismic air guns.

Ocean noise is growing from a host of military, commercial and industrial sources including dredgers that clear the seabed for ship traffic, high explosives for removing oil platforms and testing naval vessels, construction pile drivers, harassment devices for fisheries, tunnel borers, drilling platforms, oil and gas surveys, ships, and commercial and military sonar.

Intense underwater noise can harm marine life in many ways. Military sonar has been linked to dozens of mass strandings of whales around the world, and oil and gas surveys have been shown to damage fish and reduce catch rates.

"Nations of the world need to work together now to reduce the impacts of ocean noise before the problem becomes unmanageable and the harm to marine life irreversible," Jasny said.

There is no longer serious scientific debate about whether marine mammals are dying from intense ocean noise that originates from human activities, the NRDC says.

The Scientific Committee of the International Whaling Commission released a report in July saying, there is "compelling evidence" that entire populations of whales and other marine mammals are potentially threatened by increasingly intense underwater noise from human activities, both regionally and oceanwide.

The Scientific Committee expressed "great concern" over the impacts of oil and gas exploration on large whales, noting "several cases of impacts" on large whales from these activities. The report cited an incident in 2002 in which humpback whales stranded off the coast of Brazil in unusual numbers during an underwater oil and gas survey of the area that generated intense sound pulses.

According to a report in the scientific journal "Nature," cited by the NRDC, animals that came ashore during one mass stranding had developed large emboli, or bubbles, in their organ tissue. The report suggested that the animals had suffered from something akin to a severe case of the bends - the illness that can kill scuba divers who surface too quickly from deep water.

"The study supports what many scientists have long suspected: that the whales stranded on shore are only the most visible symptom of a problem affecting much larger numbers of marine life," says the NRDC report.

But despite evidence of the harm caused by human sources of ocean noise, the NRDC says there are virtually no safeguards in place to protect marine life.

NRDC began campaigning to expose the dangers of active sonar in 1994. The group accuses the U.S. government of blocking international efforts to control the problem.

Sonar technicians aboard the nuclear submarine USS Toledo monitor the sonar screens during their watch while underway in the Persian Gulf on September 1, 2004. (Photo by Petty Officer 1st class David C. Lloyd courtesy U.S. Navy)

In August 2003, the NRDC won a major victory, when a federal court ruled illegal the Navy's plan to deploy Low Frequency Active (LFA) sonar through 75 percent of the world's oceans.

After this ruling, the Navy agreed to limit use of the system to a fraction of the area originally proposed, and that use of LFA sonar will be guided by negotiated geographical limits and seasonal exclusions. Conservationists believe this will protect critical habitat and whale migrations, and the Navy also retains the flexibility it needs for training exercises. None of the limits apply during war or heightened threat conditions.

The pact demonstrates that current law can safeguard both the environment and national security, the NRDC says.

But shortly after the settlement, the Bush administration pushed legislation through Congress that exempts the U.S. military from core provisions of the Marine Mammal Protection Act, leaving the armed forces freer to harm whales, dolphins and other marine mammals in the course of using high-intensity sonar and underwater explosives.

Now that the exemptions have been granted, the administration is appealing the court ruling limiting deployment of LFA sonar. The NRDC says it stands ready to defend this "hard-won" court victory.

The NRDC report comes as the U.S. Navy is moving ahead with plans to site an Undersea Warfare Training Range off Florida, Virginia, or North Carolina, where a mass stranding of whales occurred earlier this year after a U.S. Navy sonar exercise.

The training range would be the location for over 160 sonar exercises per year, and the NRDC says it would "transform the acoustic landscape" of the region.

An undersea sonar training range already exists off the coast of Hawaii. But the Navy says another is needed to train its Atlantic fleet because of the growing threat posed by ultra-quiet diesel submarines.

Conrad Erkelens, an environmental specialist for the Navy's U.S. Pacific Fleet, says the Navy has a history of "working to protect marine mammals in the vicinity of naval activity."

Some analyses of the effect of Navy sonar on marine mammals conclude that the sonar did not cause stranding. For instance, on May 5, 2003, several civilian whale watchers vessels and local environmentalists observed orca along the shore of San Juan Island in Washington state. At this time, the USS Shoup was conducting routine training using its mid-range tactical sonar system. Although some statements in the media reported that the sonar had resulted in injury to the orca and was linked to subsequent harbor porpoise strandings, NOAA’s assessment does not support these claims.

But overall, marine mammal conservationists are not convinced that sonar is benign.

On October 19, five conservation organizations filed a lawsuit in federal court against the U.S. Navy. Whales, dolphins and other marine animals could be spared injury and death with common sense precautions, but the Navy refuses to implement them, according to the lawsuit, brought by the NRDC, the Cetacean Society International, the International Fund for Animal Welfare (IFAW), the League for Coastal Protection, and Ocean Futures Society and its founder and president Jean Michel Cousteau.

The Navy has until December 18 to respond to the legal action.

Sounding the Depths II is the second edition of a report originally published by NRDC in 1999. Sounding the Depths II sets forth a comprehensive strategy for reducing ocean noise pollution. The new edition includes:

The most comprehensive accounting of mass whale strandings related to both military sonar and high energy seismic surveys conducted by the oil and gas industry

A global map of "hotspots," showing where industry explores for oil and gas by blasting air guns at the ocean floor

A roster of active sonar systems used by U.S. and other navies

The latest scientific findings on noise and whale strandings

A chart of mitigation measures and recommendations for reducing the impacts of ocean noise

The report calls for geographic and seasonal restrictions on intense noise from military sonar and seismic air guns, technological improvements to reduce sonic damage, better monitoring and population research, stronger enforcement by the National Marine Fisheries Service, and a commitment to international solutions.